One of the First Hydrography Maps of American Southwest Based Upon Actual Surveys

Scarce map of Southern California and Part of Nevada, focused on the system which drains the various mountains and valleys in the region.

Prepared in conneciton with the Surveys West of the 100th Meridian, this map reflects the earliest systematic study of the Hydrography of Southern California and contiguous parts of Nevada drained by the Colorado River.

The map is broken into three sections, Great (San Joquin) Valley, Interior Basin and Coastal (range) Drainage, along with the Colorado (River) Desert.

The map displays an area from San Diego and Ft. Yuma in the south eat to Santa Cruz on the Pacific in the north west. the colors show drainage area and basins, while major geographic and built features are named. The "Visalia Div. S.P.R.R." runs down the Great Valley Drainage past Tulare Lake. (Tulare Lake was once the largest fresh water lake west of the Great Lakes. It is now a dry basin, "reclaimed" for agriculture and housing developments.)

The "Old Salt Lake Road" runs northwest out of the Los Angeles area through a miniscule Last Vegas. From Appendix JJ of Wheeler's 1876 Annual Report Upon the Geographical Surveys West of the 100th Meridian.